Motorola APX 7000 - Advanced Features; Bluetooth Drop Timer

Troubleshooting Charts: RX RF Failure 5-39
RX RF Failure – Page 7
5
Remove shield, SH7.
Measure RF levels at the
filter and compute filter
loss. Input side of C526
and output side of C503.
Filter Loss
<1 dB?
Measure RF levels at RF
switch, U501, output side
of C503 and input side of
C511.
U501 loss
< 3 dB?
8
Visually inspect and
replace components if
necessary.
No
Yes
No
Yes
8
Remove SH7 and SH2.
Measure RF and IF level at
mixer and compute mixer
conversion loss. Pin 1 of
T503 and Pin 1 of T504.
Mixer loss
about 6dB?
Levels between
4-8 dB are
acceptable.
No
Yes
Check digital logic
to the RF switch
and replace U501 if
needed.
13
14
Note: RF Test frequency used:
VHF: 154.275 MHz
UHF1: 424.975 MHz
UHF2: 485.075 MHz
700: 769.0625 MHz
800: 860.0625 MHz
Measured with a high impedance probe for
relative comparisons and troubleshooting only.
Actual S21 gain or loss may differ if the
test point is not 50 ohms.